The primary objective of the proposed research is to develop a set of DNA probe reagents to assay telomere integrity throughout the entire human genome. Chromosome-specific telomeric probes, in combination with centromere probes, will be a powerful set of reagents for the clinical detection of chromosome translocations, terminal deletions, and fusion events in human genetic disease and cancer. A wide variety of molecular techniques will be employed to accomplish the following specific aims: (1) to develop a complete set of chromosome-specific telomeric DNA probes optimized for fluorescence in situ hybridization (FISH). Kits are proposed for multicolored single chromosome analysis and total genome analysis. (2) To develop, for each telomeric region, multiple microsatellite and cRY(i) repeat polymorphisms (variations in purine- pyrimidine repeat DNA sequences between individuals). A PCR based kit will be developed containing primers for 150-200 polymorphic markers which will detect uniparental disomy and subtelomeric deletions and cryptic translocations associated with unexplained mental retardation, miscarriage, and spontaneous abortion. The polymorphic markers will be multiplexed for automated analysis. Chromosome-specific telomeric DNA probes will also provide tools to human genome researchers for completion of chromosome maps and for regional mapping of new DNA probes and genes. PROPOSED COMMERCIAL APPLICATION: Chromosome-specific telomeric DNA probes will be powerful diagnostic reagents for human genetic diseases and cancers typified by chromosomal rearrangements. Kits will be optimized for multicolor fluorescence in situ hybridization and a multiplexed, PCR- based, automated assay for human telomere integrity.